Each
Set-Up in the defined Observation File is oriented using one or more
orientation observations, and the T- t corrections are applied. Distances
are reduced for Scale Enlargement, Sea Level, Projection Factor and Slope.
Vertical Angles are corrected for Curvature and Refraction.

Calculation
may be in Normal, Radial or Sequential Polar mode

Reverse
Polars

Calculate
an unknown Set-Up Point [Y, X, Z] by observing to one, or more,
distant known Points (such as Trig. Stations) and observing and
measuring to a close known Point. Data are extracted from a User
defined SURPAC
Observation File.

Two
Sides and the Included Angle

Calculate
and check an unknown Set-Up Point [Y, X, Z] by observing and measuring
to two known Points. Data are extracted from a User defined SURPAC
Observation File.

Intersections

Intersection
of a new Point by "Direction and Direction" from two known
Points

Trilateration
of a new Point by Distance and Distance" from two known Points

Intersection
of a new Point by "Direction and Distance" from two known
Points

Calculate
the Tangent Point from a Point to a defined Circle

Calculate
Circular Curve information from given data

Fit
a Circular Curve through 3 defined Points

Area
Calculations

Calculate
Area and Data from Co-ordinates

Calculate
Area from Co-ordinates with Co-ordinate checking from entered Polar
data

Calculate
Area from entered Polar data, without Co-ordinate checking

Calculate
two new Points to create a defined fixed Area

Calculate
a new Point using a given Pivot Point and a defined fixed Area

Point
Off-Line Calculations

Computes
and displays the Off-Line positions of all Points lying within a
prescribed distance of a defined base line. Users may view the
Off-Line data from the line connecting two terminals, or from a Least
Squares Line of Best Fit that, uses all Points located to
determine the fit.

Existing
Points may be re-computed at their On-Line positions, or new Points
maybe computed a these positions and the original Points maintained.

Road
Apex Calculations

[Y,
X] values for a
new Point are computed at a User defined Road Apex position. Input
requirements are the left and
right Road Widths and their Directions.

Line
Running and Adjusting

[Y,
X] values of Points
are calculated along a defined base line. The base line is determined
by its User defined terminal Points. Line distances between new
Points may be singular or repeated. Line mis-closure data is displayed
after all data are entered.

Splay point Calculations

[Y,
X] values for two
new Points are computed at the defined Splay positions, one either side of the
Apex Point. Input requirements are the left and right Road Directions and the Splay
Distance.

Data
Traverse Calculations

Calculates
and adjusts a simple Traverse using plane data. The programme is
designed for use in calculating Point co-ordinates by means of
starting from a known Point on a General Plan (for example) then using
the plan Directions and Distances to compute traverse legs through a
series of Points whose co-ordinate are required. The last leg used
must close onto the first, or another, known Point. T3 different modes
of adjustment are available to the User.

Field
Traverse Calculations

Calculates
and adjusts a series of Traverse Points, using adjusted data
extracted from a User defined SURPAC
Observation File.

Each
Set-Up in the Traverse is oriented using one, or more, interior and/or
exterior orientations. The T- t corrections are also applied.

This
programme is capable of handling any planar, orthogonal System to System
transformation.

The
programme uses a Parametric non-weighted (1st Order) Least Squares adjustment technique.
Developed in-house, this technique uses the rigorous least squares
adjustment of residuals determined from the weighted centres of gravity of
the two sets of Control Points.

The
minimum requirement is two common points co-ordinate in both systems.

For
transformations (or super-positions) with more than two common points, the
transforming parameters are determined by the means of a Least Squares best
fit.

The
transformation is always carried out from some other system, to
the system as defined by thecurrent
Co-ordinate File

The
Common Point data from which the transformation is being carried out, may be
manually entered, or read from another Co-ordinate File

There
are a number of Options that may be made once a system to system
transformation has been made, viz :-

You
may DELETE a common point, or a number of common points from the
transformation and then re-run the
transformation.

You
may ADD a further common point, or a number of further common points, to
the transformation and then re-run the
transformation.

You
may EDIT any point in the transformation by re-entering its co-ordinates
and then re-run the transformation.

The transforming parameters of a previous transformation may be entered
directly to allow immediate transformation of non-common points. These
values may be entered manually, or read from an ASCII file. This file
may be re-generated immediately after carrying out a transformation.

Once correct, the transformation of non-common pointsmay be carried out.
These transformed points may be stored in the current Co-ordinate
file

.

Locate
and Mean Point Groups in a Co-ordinate File

A Point Group is defined as two, or more, Points in aCo-ordinate File that lie within a prescribed distance of one
another. The programme will search through the current Co-ordinate File,
using an alphanumeric order, looking for Points that create a Point Group.
A Point Group can consist of between 2 to 14 Points in size.

This
programme incorporates a number of useful functions. For example :-

It
may be used to search for and Display the Values of a Point that may have
been surveyed two, or more, times and Saved in the Co-ordinate File under
different Names.

It
may be used to Mean all the Points in a Point Group and then save these
meaned values in the Co-ordinate File, using a default Name or a User
entered Name.

It
may be used to Adopt either the first, or the second located Point in a
Point Group and then save this Point’s values in the Co-ordinate File ,
using a default Name or a User entered Name.

It
may be used to Delete all Points in a Point Group, other than the Point
selected as the required Point representing the Point Group.

Point Comparisons using Different Co-ordinate Files

This
programme provides the facility of comparing any two SURPACCo-ordinate Files.

The
displayed programme Screen makes allowance for defining the two required
files and for selecting the mode to be used for comparing the two files.

The
Files may be compared by using the Point Namesto identify common Points. When a matching Point is found,
the programme will compare the co-ordinates of the Point in each of the
two Files and calculate the polar values derived from the co-ordinate
differences (if any).

The
Files may also be compared by matching co-ordinates . You must set a
logical limit within which the programme must search for a matching Point.
For each Point in File No.1, the programme will search for the closest
Point, within the defined search radius, in File No. 2. When a Point is
found, the programme will calculate the polar values derived from the
co-ordinate differences of the two Points (if any).

Single Point Fixing (Resections, Intersections and Trilaterations)

The mathematical principle of this programme is the rigorous Least Squares adjustment
by the variation of co-ordinates. The "Schreiber's Elimination" technique is
used to minimize the variance-covariance matrix.

This
programme will handle any type of single Point fix using any combination of
Triangulation and/or Trilateration, as well as a Height determination for
the Free point, such as :-

Point Trilateration [Y, X], or [E, N]

Point Resection [Y, X], or [E, N]

Point Resection [Y, X, Z], or [E, N, H]

Point Resection [Z], or [H]

Point Intersection [Y, X], or [E, N]

Point Intersection [Y, X, Z], or [E, N, H]

Point Intersection [Z], or [H]

The
current Co-ordinate File is used to extract the co-ordinates of the User
defined Fixed Pointsused in the
determination of the [Y, X](or
[E, N] ) co-ordinates (and/or the Height, if required), of the new Point.

The
programme allows for the abstracting and combining of Multiple Arcs . Up to
8 Arcs (or faces) are allowed for a given Set-up. Each arc may include up to
30 sighted points. The observations are displayed showing the abstracting in
the conventional survey manner, including the Mean and the Standard
Deviation. The meaned values of the Horizontal angles, the Vertical angles
and Distances are used in the Single Point Fix calculation.

For
a Trilateration calculation, the programme will use any combination of
Forward and/or Backward measured Distances to compute the new Point. The
minimum number of distances is 3. The programme will search through the
General Observation File , or defined portion of the File and extract all
measured lines to and/or from, the new Point. All Distances will then be
reduced and used to carry out a simultaneous Least Squares fix and
adjustment of the Point’s [Y, X] (or [E, N]) ordinates.

The
Network
File Editor
includes an “Active” column, which can be set to Active or
Non-Active, for all the data lines displayed for a Single Point Fix
calculation.

A
Data Line that is defined as Active is available and will be used in the
calculation of the new Point. An Active Data Line will have a Green Tick
displayed in its “Active” column.

A
Data Line defined as Non-Active is data that exists, but which will not be
used for the current calculation. A Non-Active Data Line will have a Red
Cross displayed in its “Active” column, and the Observation information
will be displayed in red Italic text. A Data Line's Active status can be
changed using a single mouse click.

The
output, of a calculation consists of :-

the
final co-ordinates of the new Point,

the
orientation correction, in the case of a resection,

a
comparison of observed quantities with final quantities and a list of
observational residuals,

the
standard deviation of unit weight for the observation set,

the
standard error-ellipse parameters,

a
list of [Y, X](or [E, N] )
ordinate axis cuts for each ray,

a
list of input data for the height fix (if required) and the computed height
differences along with their adjustments and final values.